This is important in cases like 'got diff file.txt file.txt' which should only show the diff for file.txt once. suggested by kn@

ok stsp

Previous default output remains when test cases are run individually. ok tracey

This is a racy solution that needs to be properly implemented in the future. ok stsp

The command could fail with "got: no such entry found in tree". This problem is reproduced by the regression test added in this commit. This happened because file index entries were processed in the wrong order by diff_fileindex_dir(). To fix this, keep removed entries in the RB tree and skip them when the file index is written out, rather than removing entries from the RB tree immediately causing side-effects for RB_NEXT and friends.

and add a regress to check the revert isn't aborted anymore

Relax input path requirements of got_object_id_by_path() to make things easier to callers. Allows the revert code to pass a path from the file index in lieu of a repository path.